The purpose of this preliminary study was to determine whether low dose oral interferon alpha has any definable effect on peripheral immune function in healthy normal controls in preparation for a phase I trial of oral IFN-a in patients with relapsing-remitting multiple sclerosis. The study will establish safety, optimal dosages and specific immunological effects. IFN-a production and inducibility in lymphocytes from MS patients has been shown to be deficient and seems to parallel the severity of the disease. The results showed that IFN-a, in doses from 300 to 100,000 units over 2 weeks, was 1) nontoxic, and 2) showed modification of biological response at 30,000 units. This study led to the next pilot study, "Oral interferon alpha treatment in patients with relapsing remitting multiple sclerosis".